Uncertainty analysis of chest X-ray lung height measurements and size matching for lung transplantation

Abstract

Background: Errors in measuring chest X-ray (CXR) lung heights could contribute to the occurrence of size-mismatched lung transplant procedures. Methods:We first used Bland-Altman analysis for repeated measures to evaluate contributors to measurement error of chest X-ray lung height. We then applied error propagation theory to assess the impact of measurement error on size matching for lung transplantation.Results: A total 387 chest X-rays from twenty-five donors and twenty-five recipients were measured by two raters. Individual standard deviation for lung height differences were independent of age, sex, donor vs. recipient, diagnostic group and race/ethnicity and all were pooled for analysis. Bias between raters was 0.27 cm (±0.03) and 0.22 cm (±0.06) for the right and left lung respectively. Within subject variability was the biggest contributor to error in measurement, 2.76 cm (±0.06) and 2.78 cm (±0.2) for the right and left lung height. A height difference of 4.4 cm or more (95% CI: ±4.2, ±4.6 cm) between the donor and the recipient right lung height has to be accepted to ensure matching for at least 95% of patients with the same true lung height. This difference decreases to ±1.1 cm (95% CI: ±0.9, ±1.3 cm) when the average from all available chest X-rays is used. The probability of matching a donor and a recipient decreases with increasing true lung height difference.Conclusions: Individual chest X-ray lung heights are imprecise for the purpose of size matching in lung transplantation. Averaging chest X-rays lung heights reduced uncertainty.

Utilizing computed tomography volumetry for size matching prior to lung transplantation: a case series

“…Several methods have been utilized to estimate donor and recipient lung sizes, including submammary thoracic perimeter, thoracic height and diameter on chest X-ray (CXR), patient height, and weight ( 5 , 6 ). Although true total lung capacity (TLC) values measured by plethysmography provide accurate representations of lung volume, this testing typically cannot be obtained in critically ill organ donors ( 7 ).…”